1. Field of the Invention
The present invention relates to a data encryption/decryption method, and more particularly to a data encryption/decryption method for locking data and a corresponding mobile terminal.
2. Discussion of the Related Art
FIG. 1 is a flow chart illustrating a related art method for storing data in a mobile terminal. Referring to FIG. 1, if data (e.g., character-data, video-data, and audio-data) is applied to a mobile terminal at step S11, the mobile terminal determines the presence or absence of a protection request (i.e., a data-lock function) for the input data at step S12.
If the presence of the protection request is determined (yes at step S12), the mobile terminal establishes the lock function via a menu function at step S13 such that the lock function is established in the input data at step S14.
Generally, the related art lock function assigns a password or code to the input data so as to prevent fraudulent users other than a specific authenticated user from viewing the input data. However, the conventional lock function does not encrypt the input data.
Next, FIG. 2 is a flowchart illustrating a conventional method for allowing a mobile terminal to output data. Referring to FIG. 2, if there is a data output request for any one of various data (e.g., character-data, video-data, and audio-data, etc.) stored in the mobile terminal at step S21, the mobile terminal searches for the requested data from among the data stored in the mobile terminal at step S22.
Subsequently, the mobile terminal determines the presence or absence of a lock function in the retrieved data at step S23. If the presence of the lock function of the retrieved data is determined (yes at step S23), the mobile terminal performs a user authentication process for releasing the lock function at step S24.
If the user authentication is successful (yes at step S25), the mobile terminal outputs the requested data at step S26. Otherwise, if the user authentication fails (no at step S25), the mobile terminal may not output the requested data, or may re-attempt the user authentication process.
As described above, the related art mobile terminal has a very simple lock function for the input data. In addition, when outputting a list of data stored in the mobile terminal, the mobile terminal displays data (i.e., locked data) having the lock function and other data (i.e., unlocked data) having no lock function in different ways, such that a third party other than an authenticated user can easily distinguish between the locked data and the unlocked data. Thus, the third party may interfere with the authenticated user's privacy.
Therefore, there is a need for an improved method for allowing the third party to be unaware of the presence or absence of the lock function.